基于GF卫星解译巴丹吉林沙漠湖泊水量变化

Water Volume Change of Lakes in the Badain Jaran Desert and Its Causes Based on GF Satellite Remote Sensing Data

遥感技术作为科学、快速、大面积调查监测手段,在湖泊演化、动态变化研究中应用广泛。通过解译国产GF-1、GF-2卫星遥感影像信息,结合实地勘测,解译了巴丹吉林沙漠110个湖泊地质历史时期与现代的湖面高程和边界,总结了湖泊萎缩规律,估算了两期水量变化。结果显示:湖面高程平均降低9.76 m,面积共减少61.052 km^2(占古湖总面积的75.49%),湖泊群水量共减少4.9亿m^3,说明湖泊萎缩程度高,沙漠干旱化趋势明显;研究区古、今地下水等水位线均表现出东南高、西北低的宏观特征,反映了古、今沙漠区地下水相同的补给来源与径流条件;基底凹陷区湖泊萎缩程度较低(如苏木吉林湖),基底隆起区湖泊萎缩程度较高(如雅布赖山前湖泊),萎缩程度的差异性受区域构造基底的控制与影响。

Remote sensing technology is widely used in the study of lake evolution and dynamic changes as a scientific,rapid and large⁃scale investigation and monitoring method.This study obtained the elevations and boundaries of 110 lakes in ancient and modern in the Badain Ja⁃ran Desert,based on the GF-1 and GF-2 satellite remote sensing images and regional survey.The results show that the average lakes’ele⁃vation is decreased by 9.76 m and the area of lakes reduced totally 61.052 km^2,which accounts for 75.49%of the ancient lakes’area.The total water volume of lakes has been reduced 490 million m^3,showing high degree of shrinkage of lakes and obvious drought trend.The count⁃er lines of groundwater have the characters of higher in southeast and lower in northwest generally whether in ancient or at present and those demonstrate the source of groundwater recharge and the groundwater runoff condition remains unchanged.The lakes shrinking are obviously in the basement uplift areas(e.g.Yabulai piedmont),while lightly in the basement depression areas(e.g.Lake Sumu Jaran).The differences of lakes’shrinkage are controlled by the regional tectonic basement.